The present disclosure relates to a system and method to unload grain from a grain tank on an agricultural harvester to a transport vehicle, and specifically to an improved rear grain cart of an articulated agricultural harvester.
While the design of the grain cart in U.S. Ser. No. 14/946,842, now U.S. Pat. No. 9,901,0303, is a substantial improvement in the art, a reliable increased maximum grain unload rate was desired with decreasing power requirements therefor. Moreover, increased startup torque to the augers also was desired to guard against stall. It also was noted that the design had no inertia to be “harvested” from other turning components when the source of power to each component came from a separate source, as must be true of individual hydraulic motors.
In order to give each component adequate size to provide ample break-away torque, the displacement of each motor would have to grow to such size that, when in operation, the entire system would have required massive hydraulic flow and many large hydraulic lines going from the front module to the rear module across the articulation joint. In order to achieve desired results in a cost effective and reliable manner, it became apparent that the original design would have to be modified.
To somewhat contain costs, the smaller components needed to be powered by hydraulic motors instead of hydrostatic motors, with the incumbent requirement that maximum system pressure would be 3,000 psi rather than the 6,000 psi known for hydrostatic systems. Thereby, the amount of power that could be delivered by a given size (diameter) of conduit (hose) would by default be % of the amount that the conduit could conduct (to the rear module across the hinge joint) if the system were hydrostatic.
The presently disclosed articulated combine is based on an improved rear grain cart having improved grain handling, improved design, and improved grain unloading.